Odpowiedzi

  • Użytkownik Zadane
2013-07-17T13:02:48+02:00

1.

a)

Ob = π m

2π r = π    /:π

2r = 1

r = 1/2

P = π * r² = π * (1/2)² = 1/4 π m²


b)

Ob = 2/3 π km

2π r = 2/3 π    /:π

2r = 2/3

r = 1/3

P = π * r² = π * (1/3)² = 1/9 π km²

 

2.

a)

P = 4/9 π m²

π r² = 4/9 π    /:π

r² = 4/9

r = 2/3

Ob = 2π r = 2π * 2/3 = 4/3 π m


b)

P = 2π dm²

π r² = 2 π    /:π

r² = 2

r = √2

Ob = 2π r = 2π * √2= 2√2π dm